Ground Problem

[DieselNubie]

I have a 94 K3500 Crew Cab Pickup. I'm trying to find a ground problem. I can't seem to find any information on the web on how to look for and correct a grounding problem. :confused: I've seen several posts on the forum but no information on how to fix the problem. I'm new to working on Diesel's but can turn a wrench.

Any help would be much appreciated!!! smile.gif

[HowieE]

What area are you working on? GM grounds at different points around the truck.
In general if you have voltage to a given item (a light) and the item is not responding you can check if it is a ground problem by substituting a good known ground. Take a wire and attach it to frame metal and touch the other end of the wire to ground side of the item in question. If the item works during this test it is an open ground problem you are facing.

[MTTwister]

Whoa - easy does it Howie - cut back on the coffee. smile.gif

You've probably read up on all the possible faulty ground points - so as Howie so succintly put it - any particular problem you're trying to track down?

[DieselNubie]

Thanks for your multiple responses!!! tongue.gif

:confused: Well, it's a couple of problems. I installed a new stero system with a big speaker and a big amp to power it. My volt meter which used to read around 14V (Straight up and down) now it's about 12V. Not really enough to recharge the battery. Also, my pyrometer is moving to the bass thump. It doesn't help me a whole lot when I'm listening to music and towing since the gauge won't stay still. I found the ground wire for the gauges and grounded it directly to the battery and the gauge stays still. Looks like a cab ground problem. I'm sure the ground we used for the amp is not a good ground so I'm going to rewire the amps to the battery.

Any help would be appreciated.

[Dvldog 8793]

Howdy
Regrounding your amp wont fix the problem of a bad ground. Check/clean/replace all your ground straps from the battery back. Both Batteries should be grounded to the block, block to the cab, block to the frame, frame to the cab ect...
Make sure ALL the connections are to clean bare metal with no corrosion/paint. use star washers when you can.
Also for your high powered amps a capacitor bank maybe useful. When your hit a big bass note or something else that demands allot from your amp the Alt/battery isn't keeping up. You'll find that your amp performs better and your charging system works smoother when everything is working within it's prescribed range. Depnding on what kind of trailer you've got draining your electrical system with an amp could be bad for the brakes on your trailer.
when I was working for Motorola, we grounded all the high power radios to the battery. Not just because it is the best ground but the battery also acts as noise filter. Hope this helps!
L8r
Conley Janssen
USMC 87-93

[HowieE]

As for your voltmeter know showing 12 volts while running I suspect you have ccooked your alternator, a problem I have had. In my case it was the combined load of the trailer electrical system and an electrical cooler.
Turn the audio system off and check your output voltage at about 1000 rpm, it should be above 14 volts.

[DieselNubie]

Well, Changed out my alternator and now I'm reading close to 14 volts. Thank you all for responding. smile.gif

Now a new problem. When I step on the brake, use the trun signal or trun on the lights the volt meter drops down to 12-13 volts. Is this a grounding problem??? :confused: I know this is a stupid question but how do you solve the problem. I know you need to clean the grounds but where are the ground points located on a 94 crew cab.

Thank for any help!!!

[Dvldog 8793]

Howdy
On my 99 crew both batteries are grounded to the intake w/ large cable and also to the fender w/ smaller wire. Then the motor is grounded to the firewall and frame via a braded graound strap on the pass side in the back and down by the starter. There is also a ground from the frame to the body by the rear bumper. I have also grounded the frame/body/block/bateries in other places as well.
Hope this helps!
L8r
Conley

[jspringator]

I also grounded my batteries to each other.

[DieselNubie]

Thanks Dvldog 8793!!!

I'm slowly tracking down the grounds. smile.gif I'm reading 14.4 (+ or -) after starting the motor. The volt meter is still bouncing when I turn on the turn signal but not as bad. When I hit the brakes it drops to 12-13 volts. I'll keep cleaning and replacing the grounds.

Again, Thank you all for responding!!! smile.gif